#include <bits/stdc++.h>
#include <cstdint>
#include <sys/time.h>

typedef std::int_fast32_t  s32;
typedef std::uint_fast32_t u32;
typedef std::int_fast64_t  s64;
typedef std::uint_fast64_t u64;

const unsigned long mod = 1000000007;
const double EPS = 0.00000001;
const int INF = (1 << 30);

int main() {

  int n;
  int A[10000];

  std::cin >> n;
  for(int i = 0; i < n; ++i) {
    std::cin >> A[i];
  }

  std::sort(A, A+n);

  if( n % 2 == 0 ) {
    std::cout << (A[n/2] + A[n/2-1]) / 2.0 << std::endl;
  }
  else {
    std::cout << A[n/2] << std::endl;
  }
  
  return 0;
}